def check(text, rate=0.2):
    characters = '【】*-/\\'
    num = 0
    for ch in characters:
        if ch in text:
            num += num + text.count(ch)
    if num / len(text) > rate:
        return '垃圾邮件'
    return '正常邮件'
text = '我公【司免【开发】票微-信同*号'
print(check(text))